Search results for "MRI."

Forming-Free and Self-Rectifying Resistive Switching Effect in Anodic Titanium Dioxide-Based Memristors

2018

The paper presents the resistive switching of electroforming-free Ti/anodic- TiO 2 /Cu memristors. Anodic TiO 2 thin films were prepared by anodizing Ti layers. Microscale devices were fabricated by direct laser-assisted photolithography. Experimental results showed a bipolar and self-rectifying behavior of the devices, which could be useful for crossbar array configurations. Moreover, a gradual resistive switching of the devices in both directions was observed, indicating the presence of multi-level resistance states.

Comparative Analysis of Tagging and Feature-Tracking Cardiac MRI Techniques for the Evaluation of Cardiac Deformation

2020

[EN] Currently, there is a high prevalence of cardiovascular diseases, being the leading cause of mortality worldwide. Thus, a rapid and effective evaluation of the heart is increasingly relevant to diagnose the patient early and achieve appropriate treatment. For this reason, this study aims to compare myocardial deformation parameters such as circumferential strain (segmental, base, mid, apical and global) and global torsion values by the CMR tissue tagging reference technique in SPAMM cine images and the promising feature-tracking technique in b-SSFP cine images, in 31 healthy subjects and 35 patients diagnosed with infarct. The results obtained showed that there is a high agreement in t…

Resting state FMRI: A tool to investigate functional connectivity modulation induced by transcranial direct current stimulation of the motor network

2016

Introduction: Resting-state functional connectivity (fcMRI) represents a novel fMRI approach that allows detection of temporal correlations in spontaneous BOLD signal oscillations while subjects rest quietly in the scanner. Under resting conditions the brain is engaged in spontaneous activity that causes a low frequencies (<0.1 Hz) BOLD signal fluctuations. Functional connectivity (FC) can be defined as the synchrony of neural activity among spatially distant regions. Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that is known to modulate cortical activity and FC among brain regions, as measured by functional magnetic resonance imaging. This st…

The relationship between genetic risk variants with brain structure and function in bipolar disorder: A systematic review of genetic-neuroimaging stu…

2017

Genetic-neuroimaging paradigms could provide insights regarding the pathophysiology of bipolar disorder (BD). Nevertheless, findings have been inconsistent across studies. A systematic review of gene-imaging studies involving individuals with BD was conducted across electronic major databases from inception until January 9th, 2017. Forty-four studies met eligibility criteria (N = 2122 BD participants). Twenty-six gene variants were investigated across candidate gene studies and 4 studies used a genome-wide association approach. Replicated evidence (i.e. in &gt;2 studies) suggests that individuals with BD carrying the BDNF Val66Met risk allele could have reduced hippocampal volumes compared …

Pervasive access to MRI bias artifact suppression service on a grid.

2009

Bias artifact corrupts magnetic resonance images in such a way that the image is afflicted by illumination variations. Some of the authors proposed the Exponential Entropy Driven - Homomorphic Unsharp Masking (E2D-HUM) algorithm that corrects this artifact without any a priori hypothesis about the tissues or the Magnetic Resonance image modality. Moreover, E2D-HUM does not care about the body part under examination and does not require any particular training task. People who want to use this algorithm, which is Matlab-based, have to set their own computers in order to execute it. Furthermore, they have to be Matlab-skilled to exploit all the features of the algorithm. In our work we propos…

The “caput medusae” sign in portal hypertension

2018

CNN-Based Prostate Zonal Segmentation on T2-Weighted MR Images: A Cross-Dataset Study

2020

Prostate cancer is the most common cancer among US men. However, prostate imaging is still challenging despite the advances in multi-parametric magnetic resonance imaging (MRI), which provides both morphologic and functional information pertaining to the pathological regions. Along with whole prostate gland segmentation, distinguishing between the central gland (CG) and peripheral zone (PZ) can guide toward differential diagnosis, since the frequency and severity of tumors differ in these regions; however, their boundary is often weak and fuzzy. This work presents a preliminary study on deep learning to automatically delineate the CG and PZ, aiming at evaluating the generalization ability o…

Comparison of MRI and VQ-SPECT as a Screening Test for Patients With Suspected CTEPH: CHANGE-MRI Study Design and Rationale

2020

The diagnostic strategy for chronic thromboembolic pulmonary hypertension (CTEPH) is composed of two components required for a diagnosis of CTEPH: the presence of chronic pulmonary embolism and an elevated pulmonary artery pressure. The current guidelines require that ventilation–perfusion single-photon emission computed tomography (VQ-SPECT) is used for the first step diagnosis of chronic pulmonary embolism. However, VQ-SPECT exposes patients to ionizing radiation in a radiation sensitive population. The prospective, multicenter, comparative phase III diagnostic trial CTEPH diagnosis Europe - MRI (CHANGE-MRI, ClinicalTrials.gov identifier NCT02791282) aims to demonstrate whether functional…

Comparison of anterior cingulate vs. insular cortex as targets for real-time fMRI regulation during pain stimulation

2014

© 2014 Emmert Breimhorst Bauermann Birklein Van De Ville and Haller. Real time functional magnetic resonance imaging (rt fMRI) neurofeedback allows learning voluntary control over specific brain areas by means of operant conditioning and has been shown to decrease pain perception. To further increase the effect of rt fMRI neurofeedback on pain we directly compared two different target regions of the pain network notably the anterior insular cortex (AIC) and the anterior cingulate cortex (ACC). Participants for this prospective study were randomly assigned to two age matched groups of 14 participants each (7 females per group) for AIC and ACC feedback. First a functional localizer using bloc…

Does clinical findings correlate with magnetic resonance imaging (MRI) findings in patients with temporomandibular joint (TMJ) pain? A cross sectiona…

2019

Background Although magnetic resonance imaging (MRI) helps to clearly visualize the disorders in temporomandibular joint (TMJ), the relationship between cross-sectional and clinical findings has not been precisely established. The aim of this study was to evaluate the relationship between clinical symptoms and MRI findings in individuals with TMJ pain. Material and Methods This cross-sectional study, conducted on the clinical and MRI findings of the patients, who applied to Uşak University, Oral and Maxillofacial Surgery Clinic with TMJ pain between the years 2016-2019. The primary predictor variables were MRI findings; disc position (normal, disc displacement with reduction (DDWR), disc di…